test(gift-box): add unit tests for CLOSED/OPENING/OPEN state machine

test/unit/test_gift_box.gd

@@ -0,0 +1,63 @@
+## Tests for GiftBox — CLOSED/OPENING/OPEN state machine transitions.
+extends GutTest
+
+var _box: GiftBox
+
+
+func before_each() -> void:
+	_box = preload("res://scenes/objects/GiftBox.tscn").instantiate() as GiftBox
+	add_child_autofree(_box)
+
+
+func test_initial_state_is_closed() -> void:
+	assert_eq(_box._state, GiftBox.State.CLOSED)
+
+
+func test_ready_hides_gift_node() -> void:
+	var gift: Node2D = _box.get_node("Gift") as Node2D
+	assert_eq(gift.modulate.a, 0.0)
+
+
+func test_start_opening_transitions_to_opening() -> void:
+	_box._start_opening()
+	assert_eq(_box._state, GiftBox.State.OPENING)
+
+
+func test_on_lid_opened_transitions_to_open() -> void:
+	_box._start_opening()
+	_box._on_lid_opened()
+	assert_eq(_box._state, GiftBox.State.OPEN)
+
+
+func test_input_ignored_when_state_is_opening() -> void:
+	_box._state = GiftBox.State.OPENING
+	var event: InputEventScreenTouch = InputEventScreenTouch.new()
+	event.pressed = true
+	event.position = _box.global_position
+	_box._input(event)
+	assert_eq(_box._state, GiftBox.State.OPENING)
+
+
+func test_input_ignored_when_state_is_open() -> void:
+	_box._state = GiftBox.State.OPEN
+	var event: InputEventScreenTouch = InputEventScreenTouch.new()
+	event.pressed = true
+	event.position = _box.global_position
+	_box._input(event)
+	assert_eq(_box._state, GiftBox.State.OPEN)
+
+
+func test_tap_outside_hitbox_does_not_open() -> void:
+	var event: InputEventScreenTouch = InputEventScreenTouch.new()
+	event.pressed = true
+	event.position = _box.global_position + Vector2(200.0, 200.0)
+	_box._input(event)
+	assert_eq(_box._state, GiftBox.State.CLOSED)
+
+
+func test_release_event_does_not_open() -> void:
+	var event: InputEventScreenTouch = InputEventScreenTouch.new()
+	event.pressed = false
+	event.position = _box.global_position
+	_box._input(event)
+	assert_eq(_box._state, GiftBox.State.CLOSED)